Polyphenols are organic molecules comprising one or more aromatic nuclei having a plurality of hydroxyl groups dependent therefrom. Polyphenols are found in a variety of plant materials. One particular source of polyphenols comprises green tea, and one particular green tea derived polyphenol having high levels of activity is epigallocatechin gallate (EGCG).
Polyphenols, and green tea polyphenols in particular, have been shown to have a number of beneficial effects on the skin when applied topically. These materials have been shown to reduce skin inflammation and accelerate wound healing. In addition, polyphenols have an antioxidant effect which can reduce or alleviate skin damage resultant from aging, light exposure, chemical exposure and the like. Polyphenols have also been demonstrated to prevent or inhibit carcinogenesis, and these materials can function as ultraviolet protective agents.
In view of the foregoing, there is significant interest in the use of EGCG and other polyphenols as topical dermatological treatments. However, such polyphenolic compounds tend to be highly reactive, and hence they have poor long-term stability when disposed in solutions. Also, EGCG and like materials are fairly hydrophilic, and this inhibits their ability to penetrate the hydrophobic upper layers of the epidermis, primarily the stratum corneum, as well as the deeper, living layers. Hence, surfactants are needed to temporarily disrupt these layers so as to allow the penetration of hydrophilic polyphenols such as EGCG. Unfortunately, EGCG and other such polyphenols very often interact adversely with most surfactants and other components of solutions so as to cause precipitation, clouding, or other unwanted conditions. The foregoing problems have greatly limited the use of polyphenols in therapeutic compositions. As will be described in detail hereinbelow, the present invention is directed to compositions, methods and systems which allow for the preparation of polyphenol-based compositions which are stable in solution and have the ability to penetrate the skin; and hence overcome the foregoing problems.